Intercom Online......February 11, 1999

Research

An earthquake beneath a dormant volcano in Mammoth Mountain,
Calif., above, has caused carbon dioxide to seep from the ground at toxic
levels. At right, researchers Derrill Kerrick, professor of geosciences,
left, Giovanni Chiodini of Naples, Italy, and John Rogie, geosciences graduate
student, set up their monitoring equipment on Mammoth Mountain.

Volcanic gas releases found to be
more complex than expected

By A'ndrea MesserPublic Information

Since an earthquake rumbled beneath the volcano in 1989, carbon dioxide
has been seeping out of the ground in areas of Mammoth Mountain, Calif.,
killing trees and posing a health hazard in this ski resort area. Now, continuous
carbon dioxide monitoring by researchers shows that this gas flow is much
more complicated than previous measurements indicated.

In the past, the carbon dioxide levels seeping from the areas of tree
kill were measured once a year, said John Rogie, graduate student in geosciences.

"If the gas flux was lower than the previous year, it was thought
that the carbon dioxide degassing rate was continually decreasing,"
he said.

However, last year, Rogie monitored the area for a 24-hour period and
found that the flux of carbon dioxide varied by up to a factor of three
throughout the day.

"The 24-hour variation suggested that the system was very dynamic
and that more than a single measurement was needed to tell us if the carbon
dioxide rates were going up, staying the same or going down," said
Rogie.

Working with Derrill M. Kerrick, professor of geosciences; Michael Sorey,
U.S. Geological Survey, Menlo Park; Giovanni Chiodini, Osservatorio Vesuviano,
Naples, Italy; and Giorgio Virgili, WEST Systems, Pisa Italy, Rogie designed
a plan to continuously monitor the rate of carbon dioxide degassing in the
35-acre tree-kill area near Horseshoe Lake.

Rogie took continuous measurements of carbon dioxide flux and other environmental
variables from August until the equipment was removed in early November,
when snow levels reached more than two feet. As the snow accumulates, the
carbon dioxide concentration where the snow meets the ground, and in the
snowpack itself, builds up enormously and overwhelms the sensors.

Rogie found that the carbon dioxide flux was typically high in the afternoons
and low in the mornings, which would seem to follow the 24-hour temperature
cycle. However, the researchers have ruled out temperature as the cause
of the variation because there also was a 12-hour cycle which may be linked
to changes in barometric pressure.

"Hopefully these measurements will help us determine how environmental
factors like barometric pressure influence the degassing rate," Kerrick
said. "We want to identify changes in the rate of gas ascent from depth
by filtering out variation caused by weather-related phenomena."

This research will allow a better understanding of the dynamics of gas
emission from volcanoes and provide an immediate warning device should the
carbon dioxide emission rate suddenly increase.

Mammoth Mountain is considered to be a dormant volcano with its last
eruption some 200 years ago, but may produce as much carbon dioxide as the
active volcano Kilauea in Hawaii. Because the daily variability of carbon
dioxide degassing is large, it is currently impossible to know exactly how
much carbon dioxide is being emitted from Mammoth Mountain, but it is thought
to be in the range of 400 to 1,200 metric tons per day.

From the Experts

Power outages can threaten food safety

Weather, good or bad, is getting easier to track and predict, but the
sometimes capricious effects of bad weather -- stormy winds, torrential
rains and lightning -- can knock out a home's power supply for hours or
days. A Penn State Outreach and Cooperative Extension nutrition and food
safety specialist said during emergencies, homeowners shouldn't be in the
dark about food safety.

"When the power goes off for an hour or two, you don't have to worry
about food safety," said Cathy Guffey, extension agent in Bradford
County. "As long as you don't leave the freezer or refrigerator door
open or open the door often, your food supply should be safe."

For longer outages, Guffey suggests some tips for the well-prepared homeowner.

* Thermometers. Buy thermometers for the refrigerator and freezer
so you can track the temperature.

* Dry Ice. Adding dry ice to a freezer will stabilize temperatures
from two to four days, depending on how full the freezer is. Put it in a
cardboard box to keep it away from the contents of the freezer.

* Block Ice. Chilled temperatures can be maintained by placing
block ice in a pan or watertight container in the refrigerator.

* Examine the food. If ice crystals are visible and its temperature
has not gone above 40 degrees Fahrenheit, it is safe to refreeze. Discard
any item with a strange odor or color. If the item has thawed but is still
refrigerator cold, you can cook it and serve or refreeze the cooked dish.

According to Steve Knabel, professor of food science, some foods are
less tolerant of exposure to warming temperatures over time.